Multi component carrier (cc) scheduler

ABSTRACT

Certain aspects of the present disclosure provide a technique for wireless communications by a user equipment (UE). The UE implements the technique to select a number of component carriers (CCs) in both a first frequency range and a second frequency range. The UE determines a schedule for performing search and measurement in the selected number of CCs. The UE performs search and measurement in the selected CCs according to the determined schedule.

INTRODUCTION

Aspects of the present disclosure relate to wireless communications, andmore particularly, to techniques for scheduling multiple componentcarriers (CCs) for both a first frequency range (FR1) and a secondfrequency range (FR2).

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,broadcasts, or other similar types of services. These wirelesscommunication systems may employ multiple-access technologies capable ofsupporting communication with multiple users by sharing available systemresources with those users (e.g., bandwidth, transmit power, or otherresources). Multiple-access technologies can rely on any of codedivision, time division, frequency division orthogonal frequencydivision, single-carrier frequency division, or time divisionsynchronous code division, to name a few. These and other multipleaccess technologies have been adopted in various telecommunicationstandards to provide a common protocol that enables different wirelessdevices to communicate on a municipal, national, regional, and evenglobal level.

Although wireless communication systems have made great technologicaladvancements over many years, challenges still exist. For example,complex and dynamic environments can still attenuate or block signalsbetween wireless transmitters and wireless receivers, underminingvarious established wireless channel measuring and reporting mechanisms,which are used to manage and optimize the use of finite wireless channelresources. Consequently, there exists a need for further improvements inwireless communications systems to overcome various challenges.

SUMMARY

One aspect provides a method for wireless communication by a userequipment (UE), including: selecting a number of component carriers(CCs) in both a first frequency range and a second frequency range;determining a schedule for performing search and measurement in theselected number of CCs; and performing search and measurement in theselected CCs according to the determined schedule.

Other aspects provide: an apparatus operable, configured, or otherwiseadapted to perform the aforementioned methods as well as those describedelsewhere herein; a non-transitory, computer-readable media comprisinginstructions that, when executed by one or more processors of anapparatus, cause the apparatus to perform the aforementioned methods aswell as those described elsewhere herein; a computer program productembodied on a computer-readable storage medium comprising code forperforming the aforementioned methods as well as those describedelsewhere herein; and an apparatus comprising means for performing theaforementioned methods as well as those described elsewhere herein. Byway of example, an apparatus may comprise a processing system, a devicewith a processing system, or processing systems cooperating over one ormore networks.

The following description and the appended figures set forth certainfeatures for purposes of illustration.

BRIEF DESCRIPTION OF THE DRAWINGS

The appended figures depict certain features of the various aspectsdescribed herein and are not to be considered limiting of the scope ofthis disclosure.

FIG. 1 is a block diagram conceptually illustrating an example wirelesscommunication network.

FIG. 2 is a block diagram conceptually illustrating aspects of anexample base station (BS) and a user equipment (UE).

FIGS. 3A-3D depict various example aspects of data structures for awireless communication network.

FIG. 4A illustrates an example timeline for discontinuous reception(DRX) cycles.

FIG. 4B illustrates an example timeline for connected DRX (C-DRX)operation.

FIG. 5 depicts a table illustrating various specified search andmeasurement periodicities of different component carriers (CCs).

FIG. 6 depicts a flow diagram illustrating example operations forwireless communication by a UE.

FIG. 7 depicts example second frequency range per-band multi-CC searchand measurement scheduling.

FIG. 8 depicts example first frequency range multi-CC search andmeasurement scheduling.

FIG. 9 depicts components of an example communications device.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatuses, methods,processing systems, and computer-readable mediums for schedulingmultiple component carriers (CCs) for both a first frequency range(e.g., FR1 also referred to as “Sub-6 GHz”) and a second frequency range(e.g., FR2 also referred to as “millimeter wave” or “mmWave”).

According to certain aspects, a UE may select certain CCs (e.g., aprimary CC (PCC) and at least one secondary CC (SCC)) in both a firstfrequency range and a second frequency range. The UE may determine aschedule for performing search and measurement in the selected CCs, andthen perform search and measurement in the selected CCs according to thedetermined schedule. The schedule may be selected in an effort to enablethe UE to save power, for example, by limiting how often the UE wakes upper connected mode discontinuous reception (CDRX) cycle to perform thesearch and measurement in the selected CCs.

The techniques may allow flexible scheduling of a UE, for example, toperform search and measurement procedures on a relatively large numberof component carriers (CCs), with a limited number of narrow band (NB)radio frequency (RF) chains. The techniques may help ensure that varioustimelines (e.g., mandated by a standard specification) and performanceobjectives are met, while still saving power. In some cases, thetimelines may change for different operating modes. For example, in apanic mode (which may be enabled by a user), a UE may perform search andmeasurement more often in an attempt to avoid loss of coverage undercertain circumstances.

Introduction to Wireless Communication Networks

FIG. 1 depicts an example of a wireless communications system 100, inwhich aspects described herein may be implemented.

For example, wireless communication system 100 may include a componentcarrier (CC) component 198, which may be configured to perform, or causea user equipment (UE) 104 to perform, operations 600 of FIG. 6 toperform search and measurement operations on CCs in different frequencyranges (e.g., FR1 and FR2).

Generally, wireless communications system 100 includes base stations(BSs) 102, UEs 104, one or more core networks, such as an Evolved PacketCore (EPC) 160 and 5G Core (5GC) network 190, which interoperate toprovide wireless communications services.

BSs 102 may provide an access point to the EPC 160 and/or 5GC 190 for aUE 104, and may perform one or more of the following functions: transferof user data, radio channel ciphering and deciphering, integrityprotection, header compression, mobility control functions (e.g.,handover, dual connectivity), inter-cell interference coordination,connection setup and release, load balancing, distribution fornon-access stratum (NAS) messages, NAS node selection, synchronization,radio access network (RAN) sharing, multimedia broadcast multicastservice (MBMS), subscriber and equipment trace, RAN informationmanagement (RIM), paging, positioning, delivery of warning messages,among other functions. BSs 102 may include and/or be referred to as agNB, NodeB, eNB, ng-eNB (e.g., an eNB that has been enhanced to provideconnection to both EPC 160 and 5GC 190), an access point, a basetransceiver station, a radio base station, a radio transceiver, or atransceiver function, or a transmission reception point in variouscontexts.

BSs 102 wirelessly communicate with UEs 104 via communications links120. Each of BSs 102 may provide communication coverage for a respectivegeographic coverage area 110, which may overlap in some cases. Forexample, small cell 102′ (e.g., a low-power BS) may have a coverage area110′ that overlaps the coverage area 110 of one or more macrocells(e.g., high-power BSs).

The communication links 120 between BSs 102 and UEs 104 may includeuplink (UL) (also referred to as reverse link) transmissions from a UE104 to a BS 102 and/or downlink (DL) (also referred to as forward link)transmissions from a BS 102 to a UE 104. The communication links 120 mayuse multiple-input and multiple-output (MIMO) antenna technology,including spatial multiplexing, beamforming, and/or transmit diversityin various aspects.

Examples of UEs 104 include a cellular phone, a smart phone, a sessioninitiation protocol (SIP) phone, a laptop, a personal digital assistant(PDA), a satellite radio, a global positioning system, a multimediadevice, a video device, a digital audio player, a camera, a gameconsole, a tablet, a smart device, a wearable device, a vehicle, anelectric meter, a gas pump, a large or small kitchen appliance, ahealthcare device, an implant, a sensor/actuator, a display, or othersimilar devices. Some of UEs 104 may be internet of things (IoT) devices(e.g., parking meter, gas pump, toaster, vehicles, heart monitor, orother IoT devices), always on (AON) devices, or edge processing devices.UEs 104 may also be referred to more generally as a station, a mobilestation, a subscriber station, a mobile unit, a subscriber unit, awireless unit, a remote unit, a mobile device, a wireless device, awireless communications device, a remote device, a mobile subscriberstation, an access terminal, a mobile terminal, a wireless terminal, aremote terminal, a handset, a user agent, a mobile client, or a client.

Communications using higher frequency bands may have higher path lossand a shorter range compared to lower frequency communications.Accordingly, certain BSs 102 may utilize beamforming 182 with a UE 104to improve path loss and range. For example, the BS 102 and the UE 104may each include a plurality of antennas, such as antenna elements,antenna panels, and/or antenna arrays to facilitate the beamforming.

In some cases, a BS 102 may transmit a beamformed signal to a UE 104 inone or more transmit directions 182′. The UE 104 may receive thebeamformed signal from the BS 102 in one or more receive directions182″. The UE 104 may also transmit a beamformed signal to the BS 102 inone or more transmit directions 182″. The BS 102 may also receive thebeamformed signal from the UE 104 in one or more receive directions182′. The BS 102 and the UE 104 may then perform beam training todetermine the best receive and transmit directions for each of BS 102and UE 104. Notably, the transmit and receive directions for the BS 102may or may not be the same. Similarly, the transmit and receivedirections for the UE 104 may or may not be the same.

FIG. 2 depicts aspects of an example BS 102 and a UE 104.

Generally, BS 102 includes various processors (e.g., 220, 230, 238, and240), antennas 234 a-t (collectively 234), transceivers 232 a-t(collectively 232), which include modulators and demodulators, and otheraspects, which enable wireless transmission of data (e.g., source data212) and wireless reception of data (e.g., data sink 239). For example,BS 102 may send and receive data between itself and UE 104.

BS 102 includes controller/processor 240, which may be configured toimplement various functions related to wireless communications.

Generally, UE 104 includes various processors (e.g., 258, 264, 266, and280), antennas 252 a-r (collectively 252), transceivers 254 a-r(collectively 254), which include modulators and demodulators, and otheraspects, which enable wireless transmission of data (e.g., source data262) and wireless reception of data (e.g., data sink 260).

UE 104 includes controller/processor 280, which may be configured toimplement various functions related to wireless communications. In thedepicted example, controller/processor 280 includes a CC component 281,which may be representative of the CC component 198 of FIG. 1 . Notably,while depicted as an aspect of controller/processor 280, the CCcomponent 281 may be implemented additionally or alternatively invarious other aspects of UE 104 in other implementations.

FIGS. 3A-3D depict aspects of data structures for a wirelesscommunication network, such as wireless communication network 100 ofFIG. 1 . In particular, FIG. 3A is a diagram 300 illustrating an exampleof a first subframe within 5G (e.g., 5G NR) frame structure, FIG. 3B isa diagram 330 illustrating an example of DL channels within a 5Gsubframe, FIG. 3C is a diagram 350 illustrating an example of a secondsubframe within a 5G frame structure, and FIG. 3D is a diagram 380illustrating an example of UL channels within a 5G subframe.

Further discussions regarding FIG. 1 , FIG. 2 , and FIGS. 3A-3D areprovided later in this disclosure.

Introduction to mmWave Wireless Communications

In wireless communications, an electromagnetic spectrum is oftensubdivided into various classes, bands, channels, or other features. Thesubdivision is often provided based on wavelength and frequency, wherefrequency may also be referred to as a carrier, a subcarrier, afrequency channel, a tone, or a subband.

5G networks may utilize several frequency ranges, which in some casesare defined by a standard, such as 3rd Generation Partnership Project(3GPP) standards. For example, 3GPP technical standard TS 38.101currently defines Frequency Range 1 (FR1) as including 600 MHz-6 GHz,though specific uplink and downlink allocations may fall outside of thisgeneral range. Thus, FR1 is often referred to (interchangeably) as a“Sub-6 GHz” band.

Similarly, TS 38.101 currently defines Frequency Range 2 (FR2) asincluding 26-41 GHz, though again specific uplink and downlinkallocations may fall outside of this general range. FR2, is sometimesreferred to (interchangeably) as a “millimeter wave” (“mmW” or “mmWave”)band, despite being different from the extremely high frequency (EHF)band (30 GHz-300 GHz) that is identified by the InternationalTelecommunications Union (ITU) as a “millimeter wave” band becausewavelengths at these frequencies are between 1 millimeter and 10millimeters.

Communications using mmWave/near mmWave radio frequency band (e.g., 3GHz-300 GHz) may have higher path loss and a shorter range compared tolower frequency communications. As described above with respect to FIG.1 , a BS 102 configured to communicate using mmWave/near mmWave radiofrequency bands may utilize beamforming (e.g., 182) with a UE 104 toimprove path loss and range.

Further, as described herein, a UE implements a technique to select CCsin both FR1 and FR2, and then performs search and measurement in theselected CCs according to a schedule.

Introduction to C-DRX

As illustrated in FIG. 4A and FIG. 4B, during periods of trafficinactivity, a user equipment (UE) may switch to a connecteddiscontinuous reception (C-DRX) operation for power saving. A UE may beconfigured for C-DRX according to various configuration parameters, suchas an inactivity timer, a short DRX timer, a short DRX cycle, and a longDRX cycle.

Based on configured cycles, the UE wakes up occasionally for ONdurations and monitors for physical downlink control channel (PDCCH)transmissions. Except for ON durations, the UE may remain in a low power(sleep) state referred to as an OFF duration, for the rest of C-DRXcycle. During the OFF duration, the UE is not expected to transmit andreceive any signal.

In a C-DRX mode, a UE wakes up and transmits and/or receives (TX/RX)data packets following C-DRX cycle (during a C-DRX ON period). In somecases, if the UE detects a PDCCH scheduling data during ON duration, theUE remains ON to transmit and receive data. Otherwise, the UE goes backto sleep at the end of the ON duration. This type of C-DRX mode has beenused many years and is still default behavior of some new radio (NR)networks and UEs.

In some cases, with periodic C-DRX cycles, a UE may wake up frequentlyeven when the UE has no data to transmit and/or to monitor for data(e.g., indicated by a page), which wastes UE power. Enlarging a C-DRXcycle may cause UEs to wake up less often, but this may also lead toincreased data service latency (e.g., if a UE has packets to transmitwell before the next C-DRX on duration).

Aspects Related to Multi-CC Scheduler

A UE typically performs search and measurement in various frequencies,to support various procedures, such as handover to stronger cells oradding a new Carrier Component (CCs) in the case of Carrier Aggression(CA). When performing search and measurement, a UE measures various cellsignal strengths (using certain UE beams) of certain reference signals.For example, a UE may measure reference signal received power (RSRP) orreference signal received quality (RSRQ) of various signals transmittedin synchronization blocks (SSBs).

To maintain radio link quality and avoid drops in performance, a UE maybe configured to perform search and measurement according tostandards-specified timing requirements. A table shown in FIG. 5illustrates example search and measurement periodicity requirements fordifferent CCs for different frequency ranges under different modes.

The different modes may include an idle mode, a connected mode, a dualconnectivity (DC) carrier aggregation (CA) mode, and a connecteddiscontinuous reception (C-DRX) mode. In CA and DC modes, the differentCCs may include a primary CC (PCC), an activated secondary CC (SCC), anda deactivated SCC. The different frequency ranges include a firstfrequency range (e.g., FR1) and a second frequency range (e.g., FR2).The second frequency range spans higher frequencies than the firstfrequency range.

One challenge to meet search and measurement timing requirements is thata UE may have limited radio frequency (RF) processing resources.Depending on the operating mode, a number of narrow band (NB) RF chainsmay be more or less than the number of CCs to measure. This may resultin a UE re-tuning a same NB RF chain to different CCs at different times(e.g., according to a multi-CC scheduling technique).

For example, in some cases, a number of narrow bands (NB) chains of a UEmay be more than a number of CCs supported by the UE. In one examplecase (e.g., for a first frequency range), a UE supports 2 CCs and 4 NBchains. In such cases, the UE may be able to perform search andmeasurement in both CCs without the need to employ a multi-CC scheduler.

In other cases, a number of NB chains of a UE may be less than a numberof CCs supported by the UE. In one example case (e.g., for a secondfrequency range), a UE supports up to 8 CCs (intra-band only) and 4 NBchains. In such cases, since the UE is not able to (simultaneously)schedule all CCs due to a limited number of NB chains, the UE mayimplement a timer-based multi-CC scheduler technique. The technique mayhelp to determine a schedule for performing search and measurement inthe CCs (e.g., based on a timer maintained for each CC).

Such a multi-CC scheduling technique may be challenged to handle all usecases. For example, this technique is unable to handle a use case wherethere is only 1 NB chain. In addition, this technique does not supportuse cases where CCs may be used for inter-band carrier aggregation (CA)in the second frequency range and CA/dual connectivity (DC) in the firstand second frequency ranges (e.g., FR1 and FR2).

Aspects of the present disclosure, however, provide techniques that mayhelp enable a UE to schedule multiple CCs for both a first frequencyrange and a second frequency range, with a limited number of NB RFchains of a UE, in order to meet search and measurement periodicityrequirements for different CCs and save power.

For example, a UE may implement a technique to select CCs in both afirst frequency range and a second frequency range, and then performsearch and measurement in the selected CCs according to a schedule. Thetechniques described herein may also help enable the UE to save power asthe UE will wake up at most once per C-DRX cycle to perform the searchand measurement in the selected CCs.

FIG. 6 depicts a flow diagram illustrating example operations 600 forwireless communication. The operations 600 may be performed, forexample, by a UE (e.g., such as the UE 104 in the wireless communicationnetwork 100 of FIG. 1 ). The operations 600 may be implemented assoftware components that are executed and run on one or more processors(e.g., the controller/processor 280 of FIG. 2 ). Further, transmissionand reception of signals by the mobile repeater in operations 600 may beenabled, for example, by one or more antennas (e.g., the antennas 252 ofFIG. 2 ). In certain aspects, the transmission and/or reception ofsignals by the UE may be implemented via a bus interface of one or moreprocessors (e.g., the controller/processor 280) obtaining and/oroutputting signals.

The operations 600 begin, at 610, by selecting a number of CCs in both afirst frequency range and a second frequency range. For example, the UEmay select the CCs in both the first frequency range and the secondfrequency range using a processor, antenna(s) and/or transceivercomponents of the UE 104 shown in FIG. 1 or FIG. 2 and/or of theapparatus shown in FIG. 9 .

At 620, the UE determines a schedule for performing search andmeasurement in the selected number of CCs. The UE may determine theschedule for performing the search and measurement in the selectednumber of CCs using a processor, antenna(s) and/or transceivercomponents of the UE 104 shown in FIG. 1 or FIG. 2 and/or of theapparatus shown in FIG. 9 .

At 630, the UE performs search and measurement in the selected CCsaccording to the determined schedule. The UE may perform the search andmeasurement in the selected CCs using a processor, antenna(s) and/ortransceiver components of the UE 104 shown in FIG. 1 or FIG. 2 and/or ofthe apparatus shown in FIG. 9 .

The operations shown in FIG. 6 may be understood with reference to FIGS.7 and 8 .

In some scenarios, a number of CCs selected by a UE in both a firstfrequency range and a second frequency range exceeds a number of NB RFchains of the UE. In one example, the number of CCs are used for DCinvolving different radio access technologies in the first and secondfrequency ranges. In another example, the number of CCs are used for CAin the first frequency range. In another example, the number of CCs areused for the CA in the second frequency range.

In certain aspects, a UE performs search and measurement in selected CCsusing a plurality of UE beams. In one example, the UE beams may includepseudo-omni (PO) beams (e.g., 8 PO beams). As used in this context, theterm Pseudo-Omni generally refers a beam or collective set of beams(e.g., swept in sequence) to provide near omni-directional (e.g., 360°horizontal) coverage.

In certain aspects, one NB RF chain is reserved for each frequency band(e.g., up to 2 frequency bands) of a second frequency range. In certainaspects, a single NB RF chain is used for search and measurement in allintra-band CCs (e.g., up to 8 CCs) of each frequency band of the secondfrequency range.

In certain aspects, a schedule determined by a UE may dictate beamsweeping a plurality of UE beams to perform search and measurement on aPCC at a first periodicity (e.g., using a different PO beam eachperiod), and using a selected one of the plurality of swept UE beams toperform search and measurement on at least one SCC at a secondperiodicity. The UE may select the UE beam used to perform the searchand measurement on the at least one SCC based on the beam sweeping ofthe plurality of UE beams to perform the search and measurement on thePCC.

As illustrated in FIG. 7 , a UE may sweep (e.g., according to a roundrobin schedule) over all PO beams on a PCC, for example, per a firsttimeline 700, to meet a specification requirement, and per a secondtimeline 710, panic mode requirement for search and measurement on thePCC). The illustrated example assumes eight PO beams (e.g., PO 0 to PO7).

As illustrated, a different PO beam is used to perform the search andmeasurement on the PCC every 160 ms or 8 C-DRX cycles. In the panicmode, a different PO beam is used to perform the search and measurementon the PCC every 40 ms or 1 C-DRX cycle. The UE may select a best PObeam from these PO beams (e.g., derived from the PCC). The UE uses theselected PO beam to perform the search and measurement on the SCC (e.g.,SCC 0). In this illustrated example, it may be assumed that allintra-band SCCs are quasi-colocated (QCL)ed with the PCC (e.g., meaningit may be assumed they share certain channel characteristics).

In certain aspects, at least two NB RF chains are reserved for a firstfrequency range. In certain aspects, the UE may determine a schedulebased on a timer (e.g., CC_timer) maintained by the UE for each CC(e.g., intra-band or inter-band CC) of the first frequency range. In oneexample, the timer maintained for each CC records remaining time until anext scheduling for each CC. A small value of the timer maintained forone CC may indicate this CC has a high priority (e.g., the UE has toperform search and measurement in this CC), and will rank high in acandidate CC list.

The UE may select a number of CCs corresponding to a number of availableNB RF chains of the UE, based on values of the timers maintained foreach CC of the first frequency range. For example, if there are “K”available NB RF chains of the UE, the UE selects top K CCs. In certainaspects, if multiple CCs have a same timer value, a CC with a shorterperiodicity is given higher priority than a CC with a longerperiodicity. For example, a PCC has higher priority than an activatedSCC, and the activated SCC has a higher priority than a deactivated SCC.

As illustrated in FIG. 8 , a UE selects PCC and 4 SCCs (e.g., SCC 0 toSCC 3) based on values of timers maintained for each CC of a firstfrequency range. The UE then performs search and measurement in the CCsusing UE beams. As illustrated, per a first timeline 800, UE beams areused to perform the search and measurement on the PCC/SCC every 320 msor 4 C-DRX cycles. In the panic mode, per a second timeline 810, UEbeams are used to perform the search and measurement on the PCC/SCCevery 80 ms or 1 C-DRX cycle.

As noted above, the techniques described herein may be applicable forfollowing use cases where a number of CCs exceeds a number of NB RFchains of a UE.

In one example case (e.g., for a first frequency range only), a UE maysupport 6 CCs (1 PCC and 5 SCCs) for intra- or inter-band. In anotherexample case (e.g., for a second frequency range only), a UE may support8 CCs (1 PCC and 7 SCCs) for intra-band, and 4CCs (1 PCC and 3 SCCs)*2bands (for inter-band). In another example case (e.g., a first frequencyrange and a second frequency range (DC/CA)), a UE may support 4 CCs (1PCC and 3 SCCs) for the first frequency range, 8CCs (1PCC and 7 SCCs)for second frequency range intra-band, and 4CCs (1PCC and 3 SCCs)*2bands for second frequency range inter-band.

Example Wireless Communication Device

FIG. 9 depicts an example communications device 900 that includesvarious components operable, configured, or adapted to performoperations for the techniques disclosed herein, such as the operationsdepicted and described with respect to FIG. 6 . In some examples,communication device 900 may be a user equipment (UE) 104 as described,for example with respect to FIGS. 1 and 2 .

Communications device 900 includes a processing system 902 coupled to atransceiver 908 (e.g., a transmitter and/or a receiver). Transceiver 908is configured to transmit (or send) and receive signals for thecommunications device 900 via an antenna 910, such as the varioussignals as described herein. Processing system 902 may be configured toperform processing functions for communications device 900, includingprocessing signals received and/or to be transmitted by communicationsdevice 900.

Processing system 902 includes one or more processors 920 coupled to acomputer-readable medium/memory 930 via a bus 906. In certain aspects,computer-readable medium/memory 930 is configured to store instructions(e.g., computer-executable code) that when executed by the one or moreprocessors 920, cause the one or more processors 920 to perform theoperations illustrated in FIG. 6 , or other operations for performingthe various techniques discussed herein.

In the depicted example, computer-readable medium/memory 930 stores code931 for selecting a number of component carriers (CCs) in both a firstfrequency range and a second frequency range, code 932 for determining aschedule for performing search and measurement in the selected number ofCCs, and code 933 for performing search and measurement in the selectedCCs according to the determined schedule.

In the depicted example, the one or more processors 920 includecircuitry configured to implement the code stored in thecomputer-readable medium/memory 930, including circuitry 921 forselecting a number of CCs in both a first frequency range and a secondfrequency range, circuitry 922 for determining a schedule for performingsearch and measurement in the selected number of CCs, and circuitry 923for performing search and measurement in the selected CCs according tothe determined schedule.

Various components of communications device 900 may provide means forperforming the methods described herein, including with respect to FIG.6 .

In some examples, means for transmitting or sending (or means foroutputting for transmission) may include the transceivers 254 and/orantenna(s) 252 of the UE 104 illustrated in FIG. 2 and/or transceiver908 and antenna 910 of the communication device 900 in FIG. 9 .

In some examples, means for receiving (or means for obtaining) mayinclude the transceivers 254 and/or antenna(s) 252 of the UE 104illustrated in FIG. 2 and/or transceiver 908 and antenna 910 of thecommunication device 900 in FIG. 9 .

In some examples, means for selecting a number of CCs in both a firstfrequency range and a second frequency range, means for determining aschedule for performing search and measurement in the selected number ofCCs, and means for performing search and measurement in the selected CCsaccording to the determined schedule, may include various processingsystem components, such as: the one or more processors 920 in FIG. 9 ,or aspects of the UE 104 depicted in FIG. 2 , including receiveprocessor 258, transmit processor 264, TX MIMO processor 266, and/orcontroller/processor 280 (including CC component 281).

Notably, FIG. 9 is an example, and many other examples andconfigurations of communication device 900 are possible.

Example Clauses

Implementation examples are described in the following numbered clauses:

Clause 1: A method for wireless communication by a user equipment (UE),comprising: selecting a number of component carriers (CCs) in both afirst frequency range and a second frequency range; determining aschedule for performing search and measurement in the selected number ofCCs; and performing search and measurement in the selected CCs accordingto the determined schedule.

Clause 2: The method of Clause 1, wherein the number of CCs exceeds anumber of narrow band (NB) radio frequency (RF) chains of the UE.

Clause 3: The method of any one of Clauses 1-2, wherein the number ofCCs are used for at least one of: dual connectivity (DC) involvingdifferent radio access technologies in the first and second frequencyranges; or carrier aggregation (CA) in at least one of the first andsecond frequency ranges.

Clause 4: The method of any one of Clauses 1-3, wherein the search andmeasurement is performed in the selected CCs using a plurality of UEbeams.

Clause 5: The method of any one of Clauses 1-4, wherein: the secondfrequency range spans higher frequencies than the first frequency range;and one narrow band (NB) radio frequency (RF) chain is reserved for eachfrequency band of the second frequency range.

Clause 6: The method of any one of Clauses 1-5, wherein a single NB RFchain is used for search and measurement in all intra-band CCs of eachfrequency band.

Clause 7: The method of any one of Clauses 1-6, wherein the scheduledictates: beam sweeping a plurality of UE beams to perform search andmeasurement on a primary CC (PCC) at a first periodicity; and using aselected one of the plurality of UE beams to perform search andmeasurement on at least one secondary CC (SCC) at a second periodicity.

Clause 8: The method of any one of Clauses 1-7, selecting the UE beamused to perform search and measurement on the at least one SCC based onthe beam sweeping of the plurality of UE beams to perform search andmeasurement on the PCC.

Clause 9: The method of any one of Clauses 1-8, wherein: the secondfrequency range spans higher frequencies than the first frequency range;and at least two narrow band (NB) radio frequency (RF) chains arereserved for the first frequency range.

Clause 10: The method of any one of Clauses 1-9, wherein the schedule isbased on a timer maintained for each CC of the first frequency range.

Clause 11: The method of any one of Clauses 1-10, wherein a number ofCCs, corresponding to a number of available narrow band (NB) radiofrequency (RF) chains of the UE, are selected based on values of thetimers maintained for each CC of the first frequency range.

Clause 12: The method of any one of Clauses 1-11, wherein, if multipleCCs have a same timer value, a CC with a shorter periodicity is givenhigher priority than a CC with a longer periodicity.

Clause 13: An apparatus, comprising: a memory comprising executableinstructions; one or more processors configured to execute theexecutable instructions and cause the apparatus to perform a method inaccordance with any one of Clauses 1-12.

Clause 14: An apparatus, comprising means for performing a method inaccordance with any one of Clauses 1-12.

Clause 15: A non-transitory computer-readable medium comprisingexecutable instructions that, when executed by one or more processors ofan apparatus, cause the apparatus to perform a method in accordance withany one of Clauses 1-12.

Clause 16: A computer program product embodied on a computer-readablestorage medium comprising code for performing a method in accordancewith any one of Clauses 1-12.

Additional Wireless Communication Network Considerations

The techniques and methods described herein may be used for variouswireless communications networks (or wireless wide area network (WWAN))and radio access technologies (RATs). While aspects may be describedherein using terminology commonly associated with 3G, 4G, and/or 5G(e.g., 5G new radio (NR)) wireless technologies, aspects of the presentdisclosure may likewise be applicable to other communication systems andstandards not explicitly mentioned herein.

5G wireless communication networks may support various advanced wirelesscommunication services, such as enhanced mobile broadband (eMBB),millimeter wave (mmWave), machine type communications (MTC), and/ormission critical targeting ultra-reliable, low-latency communications(URLLC). These services, and others, may include latency and reliabilityrequirements.

Returning to FIG. 1 , various aspects of the present disclosure may beperformed within the example wireless communication network 100.

In 3GPP, the term “cell” can refer to a coverage area of a NodeB and/ora narrowband subsystem serving this coverage area, depending on thecontext in which the term is used. In NR systems, the term “cell” andbase station (BS) 102, next generation NodeB (gNB or gNodeB), accesspoint (AP), distributed unit (DU), carrier, or transmission receptionpoint may be used interchangeably. A BS 102 may provide communicationcoverage for a macro cell, a pico cell, a femto cell, and/or other typesof cells.

A macro cell may generally cover a relatively large geographic area(e.g., several kilometers in radius) and may allow unrestricted accessby user equipments (UEs) 104 with service subscription. A pico cell maycover a relatively small geographic area (e.g., a sports stadium) andmay allow unrestricted access by UEs 104 with service subscription. Afemto cell may cover a relatively small geographic area (e.g., a home)and may allow restricted access by UEs 104 having an association withthe femto cell (e.g., UEs in a Closed Subscriber Group (CSG) and UEs 104for users in the home). A BS 102 for a macro cell may be referred to asa macro BS. ABS 102 for a pico cell may be referred to as a pico BS. ABS 102 for a femto cell may be referred to as a femto BS, home BS, or ahome NodeB.

BSs 102 configured for 4G LTE (collectively referred to as EvolvedUniversal Mobile Telecommunications System (UMTS) Terrestrial RadioAccess Network (E-UTRAN)) may interface with the EPC 160 through firstbackhaul links (e.g., an 51 interface). BSs 102 configured for 5G (e.g.,5G NR or Next Generation RAN (NG-RAN)) may interface with 5GC 130through second backhaul links 184. BSs 102 may communicate directly orindirectly (e.g., through the EPC 160 or 5GC 130) with each other overthird backhaul links 134 (e.g., X2 interface). Third backhaul links 134may generally be wired or wireless.

Small cell 102′ may operate in a licensed and/or an unlicensed frequencyspectrum. When operating in an unlicensed frequency spectrum, the smallcell 102′ may employ NR and use the same 5 GHz unlicensed frequencyspectrum as used by the Wi-Fi AP 150. Small cell 102′, employing NR inan unlicensed frequency spectrum, may boost coverage to and/or increasecapacity of the access network.

Some BSs 102, such as gNB 180 may operate in a traditional sub-6 GHzspectrum, in millimeter wave (mmWave) frequencies, and/or near mmWavefrequencies in communication with the UE 104. When the gNB 180 operatesin mmWave or near mmWave frequencies, the gNB 180 may be referred to asan mmWave BS.

The communication links 120 between BSs 102 and, for example, UEs 104,may be through one or more carriers. For example, BSs 102 and UEs 104may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, and otherMHz) bandwidth per carrier allocated in a carrier aggregation of up to atotal of Yx MHz (x component carriers) used for transmission in eachdirection. The carriers may or may not be adjacent to each other.Allocation of carriers may be asymmetric with respect to downlink (DL)and uplink (UL) (e.g., more or fewer carriers may be allocated for DLthan for UL). The component carriers may include a primary componentcarrier and one or more secondary component carriers. A primarycomponent carrier may be referred to as a primary cell (PCell) and asecondary component carrier may be referred to as a secondary cell(SCell).

Wireless communications system 100 further includes a Wi-Fi access point(AP) 150 in communication with Wi-Fi stations (STAs) 152 viacommunication links 154 in, for example, a 2.4 GHz and/or 5 GHzunlicensed frequency spectrum. When communicating in an unlicensedfrequency spectrum, the STAs 152/AP 150 may perform a clear channelassessment (CCA) prior to communicating in order to determine whetherthe channel is available.

Certain UEs 104 may communicate with each other using device-to-device(D2D) communication link 158. The D2D communication link 158 may use theDL/UL WWAN spectrum. The D2D communication link 158 may use one or moresidelink channels, such as a physical sidelink broadcast channel(PSBCH), a physical sidelink discovery channel (PSDCH), a physicalsidelink shared channel (PSSCH), and a physical sidelink control channel(PSCCH). D2D communication may be through a variety of wireless D2Dcommunications systems, such as for example, FlashLinQ, WiMedia,Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, 4G (e.g.,LTE), or 5G (e.g., NR), to name a few options.

EPC 160 may include a Mobility Management Entity (MME) 162, other MMES164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service(MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170,and a Packet Data Network (PDN) Gateway 172. MME 162 may be incommunication with a Home Subscriber Server (HSS) 174. MME 162 is thecontrol node that processes the signaling between the UEs 104 and theEPC 160. Generally, MME 162 provides bearer and connection management.

Generally, user Internet protocol (IP) packets are transferred throughServing Gateway 166, which itself is connected to PDN Gateway 172. PDNGateway 172 provides UE IP address allocation as well as otherfunctions. PDN Gateway 172 and the BM-SC 170 are connected to the IPServices 176, which may include, for example, the Internet, an intranet,an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or otherIP services.

BM-SC 170 may provide functions for MBMS user service provisioning anddelivery. BM-SC 170 may serve as an entry point for content providerMBMS transmission, may be used to authorize and initiate MBMS BearerServices within a public land mobile network (PLMN), and may be used toschedule MBMS transmissions. MBMS Gateway 168 may be used to distributeMBMS traffic to the BSs 102 belonging to a Multicast Broadcast SingleFrequency Network (MBSFN) area broadcasting a particular service, andmay be responsible for session management (start/stop) and forcollecting eMBMS related charging information.

5GC 130 may include an Access and Mobility Management Function (AMF)132, other AMFs 133, a Session Management Function (SMF), and a UserPlane Function (UPF) 135. AMF 132 may be in communication with a UnifiedData Management (UDM) 136.

AMF 132 is generally the control node that processes the signalingbetween UEs 104 and 5GC 130. Generally, AMF 132 provides QoS flow andsession management.

All user Internet protocol (IP) packets are transferred through UPF 135,which is connected to the IP Services 137, and which provides UE IPaddress allocation as well as other functions for 5GC 130. IP Services137 may include, for example, the Internet, an intranet, an IPMultimedia Subsystem (IMS), a PS Streaming Service, and/or other IPservices.

Returning to FIG. 2 , various example components of BS 102 and UE 104(e.g., the wireless communication network 100 of FIG. 1 ) are depicted,which may be used to implement aspects of the present disclosure.

At BS 102, a transmit processor 220 may receive data from a data source212 and control information from a controller/processor 240. The controlinformation may be for the physical broadcast channel (PBCH), physicalcontrol format indicator channel (PCFICH), physical hybrid ARQ indicatorchannel (PHICH), physical downlink control channel (PDCCH), group commonPDCCH (GC PDCCH), and others. The data may be for the physical downlinkshared channel (PDSCH), in some examples.

A medium access control (MAC)-control element (MAC-CE) is a MAC layercommunication structure that may be used for control command exchangebetween wireless nodes. The MAC-CE may be carried in a shared channelsuch as a physical downlink shared channel (PDSCH), a physical uplinkshared channel (PUSCH), or a physical sidelink shared channel (PSSCH).

Processor 220 may process (e.g., encode and symbol map) the data andcontrol information to obtain data symbols and control symbols,respectively. Transmit processor 220 may also generate referencesymbols, such as for the primary synchronization signal (PSS), secondarysynchronization signal (SSS), PBCH demodulation reference signal (DMRS),and channel state information reference signal (CSI-RS).

Transmit (TX) multiple-input multiple-output (MIMO) processor 230 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODs) in transceivers232 a-232 t. Each modulator in transceivers 232 a-232 t may process arespective output symbol stream (e.g., for OFDM) to obtain an outputsample stream. Each modulator may further process (e.g., convert toanalog, amplify, filter, and upconvert) the output sample stream toobtain a downlink signal. Downlink signals from the modulators intransceivers 232 a-232 t may be transmitted via the antennas 234 a-234t, respectively.

At UE 104, antennas 252 a-252 r may receive the downlink signals fromthe BS 102 and may provide received signals to the demodulators (DEMODs)in transceivers 254 a-254 r, respectively. Each demodulator intransceivers 254 a-254 r may condition (e.g., filter, amplify,downconvert, and digitize) a respective received signal to obtain inputsamples. Each demodulator may further process the input samples (e.g.,for OFDM) to obtain received symbols.

MIMO detector 256 may obtain received symbols from all the demodulatorsin transceivers 254 a-254 r, perform MIMO detection on the receivedsymbols if applicable, and provide detected symbols. Receive processor258 may process (e.g., demodulate, deinterleave, and decode) thedetected symbols, provide decoded data for the UE 104 to a data sink260, and provide decoded control information to a controller/processor280.

On the uplink, at UE 104, transmit processor 264 may receive and processdata (e.g., for the physical uplink shared channel (PUSCH)) from a datasource 262 and control information (e.g., for the physical uplinkcontrol channel (PUCCH) from the controller/processor 280. Transmitprocessor 264 may also generate reference symbols for a reference signal(e.g., for the sounding reference signal (SRS)). The symbols from thetransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by the modulators in transceivers 254a-254 r (e.g., for SC-FDM), and transmitted to BS 102.

At BS 102, the uplink signals from UE 104 may be received by antennas234 a-t, processed by the demodulators in transceivers 232 a-232 t,detected by a MIMO detector 236 if applicable, and further processed bya receive processor 238 to obtain decoded data and control informationsent by UE 104. Receive processor 238 may provide the decoded data to adata sink 239 and the decoded control information to thecontroller/processor 240.

Memories 242 and 282 may store data and program codes for BS 102 and UE104, respectively.

Scheduler 244 may schedule UEs for data transmission on the downlinkand/or uplink.

5G may utilize orthogonal frequency division multiplexing (OFDM) with acyclic prefix (CP) on the uplink and downlink. 5G may also supporthalf-duplex operation using time division duplexing (TDD). OFDM andsingle-carrier frequency division multiplexing (SC-FDM) partition thesystem bandwidth into multiple orthogonal subcarriers, which are alsocommonly referred to as tones and bins. Each subcarrier may be modulatedwith data. Modulation symbols may be sent in the frequency domain withOFDM and in the time domain with SC-FDM. The spacing between adjacentsubcarriers may be fixed, and the total number of subcarriers may bedependent on the system bandwidth. The minimum resource allocation,called a resource block (RB), may be 12 consecutive subcarriers in someexamples. The system bandwidth may also be partitioned into subbands.For example, a subband may cover multiple RBs. NR may support a basesubcarrier spacing (SCS) of 15 KHz and other SCS may be defined withrespect to the base SCS (e.g., 30 kHz, 60 kHz, 120 kHz, 240 kHz, andothers).

As above, FIGS. 3A-3D depict various example aspects of data structuresfor a wireless communication network, such as wireless communicationnetwork 100 of FIG. 1 .

In various aspects, the 5G frame structure may be frequency divisionduplex (FDD), in which for a particular set of subcarriers (carriersystem bandwidth), subframes within the set of subcarriers are dedicatedfor either DL or UL. 5G frame structures may also be time divisionduplex (TDD), in which for a particular set of subcarriers (carriersystem bandwidth), subframes within the set of subcarriers are dedicatedfor both DL and UL. In the examples provided by FIGS. 3A and 3C, the 5Gframe structure is assumed to be TDD, with subframe 4 being configuredwith slot format 28 (with mostly DL), where D is DL, U is UL, and X isflexible for use between DL/UL, and subframe 3 being configured withslot format 34 (with mostly UL). While subframes 3, 4 are shown withslot formats 34, 28, respectively, any particular subframe may beconfigured with any of the various available slot formats 0-61. Slotformats 0, 1 are all DL, UL, respectively. Other slot formats 2-61include a mix of DL, UL, and flexible symbols. UEs are configured withthe slot format (dynamically through DL control information (DCI), orsemi-statically/statically through radio resource control (RRC)signaling) through a received slot format indicator (SFI). Note that thedescription below applies also to a 5G frame structure that is TDD.

Other wireless communication technologies may have a different framestructure and/or different channels. A frame (10 ms) may be divided into10 equally sized subframes (1 ms). Each subframe may include one or moretime slots. Subframes may also include mini-slots, which may include 7,4, or 2 symbols. In some examples, each slot may include 7 or 14symbols, depending on the slot configuration.

For example, for slot configuration 0, each slot may include 14 symbols,and for slot configuration 1, each slot may include 7 symbols. Thesymbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. Thesymbols on UL may be CP-OFDM symbols (for high throughput scenarios) ordiscrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (alsoreferred to as single carrier frequency-division multiple access(SC-FDMA) symbols) (for power limited scenarios; limited to a singlestream transmission).

The number of slots within a subframe is based on the slot configurationand the numerology. For slot configuration 0, different numerologies 0to 5 allow for 1, 2, 4, 8, 16, and 32 slots, respectively, per subframe.For slot configuration 1, different numerologies 0 to 2 allow for 2, 4,and 8 slots, respectively, per subframe. Accordingly, for slotconfiguration 0 and numerology μ, there are 14 symbols/slot and 2μslots/subframe. The subcarrier spacing and symbol length/duration are afunction of the numerology. The subcarrier spacing may be equal to2^(μ)×15 kHz, where μ is the numerology 0 to 5. As such, the numerologyμ=0 has a subcarrier spacing of 15 kHz and the numerology μ=5 has asubcarrier spacing of 480 kHz. The symbol length/duration is inverselyrelated to the subcarrier spacing. FIGS. 3A-3D provide an example ofslot configuration 0 with 14 symbols per slot and numerology μ=2 with 4slots per subframe. The slot duration is 0.25 ms, the subcarrier spacingis 60 kHz, and the symbol duration is approximately 16.67 μs.

A resource grid may be used to represent the frame structure. Each timeslot includes a resource block (RB) (also referred to as physical RBs(PRBs)) that extends 12 consecutive subcarriers. The resource grid isdivided into multiple resource elements (REs). The number of bitscarried by each RE depends on the modulation scheme.

As illustrated in FIG. 3A, some of the REs carry reference (pilot)signals (RS) for a UE (e.g., UE 104 of FIGS. 1 and 2 ). The RS mayinclude demodulation RS (DM-RS) (indicated as Rx for one particularconfiguration, where 100× is the port number, but other DM-RSconfigurations are possible) and channel state information referencesignals (CSI-RS) for channel estimation at the UE. The RS may alsoinclude beam measurement RS (BRS), beam refinement RS (BRRS), and phasetracking RS (PT-RS).

FIG. 3B illustrates an example of various DL channels within a subframeof a frame. The physical downlink control channel (PDCCH) carries DCIwithin one or more control channel elements (CCEs), each CCE includingnine RE groups (REGs), each REG including four consecutive REs in anOFDM symbol.

A primary synchronization signal (PSS) may be within symbol 2 ofparticular subframes of a frame. The PSS is used by a UE (e.g., 104 ofFIGS. 1 and 2 ) to determine subframe/symbol timing and a physical layeridentity.

A secondary synchronization signal (SSS) may be within symbol 4 ofparticular subframes of a frame. The SSS is used by a UE to determine aphysical layer cell identity group number and radio frame timing.

Based on the physical layer identity and the physical layer cellidentity group number, the UE can determine a physical cell identifier(PCI). Based on the PCI, the UE can determine the locations of theaforementioned DM-RS. The physical broadcast channel (PBCH), whichcarries a master information block (MIB), may be logically grouped withthe PSS and SSS to form a synchronization signal (SS)/PBCH block. TheMIB provides a number of RBs in the system bandwidth and a system framenumber (SFN). The physical downlink shared channel (PDSCH) carries userdata, broadcast system information not transmitted through the PBCH suchas system information blocks (SIBs), and paging messages.

As illustrated in FIG. 3C, some of the REs carry DM-RS (indicated as Rfor one particular configuration, but other DM-RS configurations arepossible) for channel estimation at the BS. The UE may transmit DM-RSfor the physical uplink control channel (PUCCH) and DM-RS for thephysical uplink shared channel (PUSCH). The PUSCH DM-RS may betransmitted in the first one or two symbols of the PUSCH. The PUCCHDM-RS may be transmitted in different configurations depending onwhether short or long PUCCHs are transmitted and depending on theparticular PUCCH format used. The UE may transmit sounding referencesignals (SRS). The SRS may be transmitted in the last symbol of asubframe. The SRS may have a comb structure, and a UE may transmit SRSon one of the combs. The SRS may be used by a BS for channel qualityestimation to enable frequency-dependent scheduling on the UL.

FIG. 3D illustrates an example of various UL channels within a subframeof a frame. The PUCCH may be located as indicated in one configuration.The PUCCH carries uplink control information (UCI), such as schedulingrequests, a channel quality indicator (CQI), a precoding matrixindicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. ThePUSCH carries data, and may additionally be used to carry a bufferstatus report (BSR), a power headroom report (PHR), and/or UCI.

ADDITIONAL CONSIDERATIONS

The preceding description provides examples of scheduling multiplecomponent carriers (CCs) for both FR1 and FR2 in communication systems.The preceding description is provided to enable any person skilled inthe art to practice the various aspects described herein. The examplesdiscussed herein are not limiting of the scope, applicability, oraspects set forth in the claims. Various modifications to these aspectswill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other aspects. For example,changes may be made in the function and arrangement of elementsdiscussed without departing from the scope of the disclosure. Variousexamples may omit, substitute, or add various procedures or componentsas appropriate. For instance, the methods described may be performed inan order different from that described, and various steps may be added,omitted, or combined. Also, features described with respect to someexamples may be combined in some other examples. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, the scope of thedisclosure is intended to cover such an apparatus or method that ispracticed using other structure, functionality, or structure andfunctionality in addition to, or other than, the various aspects of thedisclosure set forth herein. It should be understood that any aspect ofthe disclosure disclosed herein may be embodied by one or more elementsof a claim.

The techniques described herein may be used for various wirelesscommunication technologies, such as 5G (e.g., 5G NR), 3GPP Long TermEvolution (LTE), LTE-Advanced (LTE-A), code division multiple access(CDMA), time division multiple access (TDMA), frequency divisionmultiple access (FDMA), orthogonal frequency division multiple access(OFDMA), single-carrier frequency division multiple access (SC-FDMA),time division synchronous code division multiple access (TD-SCDMA), andother networks. The terms “network” and “system” are often usedinterchangeably. A CDMA network may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, and others. UTRAincludes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implementa radio technology such as Global System for Mobile Communications(GSM). An OFDMA network may implement a radio technology such as NR(e.g. 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, andothers. UTRA and E-UTRA are part of Universal Mobile TelecommunicationSystem (UMTS). LTE and LTE-A are releases of UMTS that use E-UTRA. UTRA,E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from anorganization named “3rd Generation Partnership Project” (3GPP). cdma2000and UMB are described in documents from an organization named “3rdGeneration Partnership Project 2” (3GPP2). NR is an emerging wirelesscommunications technology under development.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a DSP, an ASIC, a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, a system on a chip(SoC), or any other such configuration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a UE (seeFIG. 1 ), a user interface (e.g., keypad, display, mouse, joystick,touchscreen, biometric sensor, proximity sensor, light emitting element,and others) may also be connected to the bus. The bus may also linkvarious other circuits such as timing sources, peripherals, voltageregulators, power management circuits, and the like, which are wellknown in the art, and therefore, will not be described any further. Theprocessor may be implemented with one or more general-purpose and/orspecial-purpose processors. Examples include microprocessors,microcontrollers, DSP processors, and other circuitry that can executesoftware. Those skilled in the art will recognize how best to implementthe described functionality for the processing system depending on theparticular application and the overall design constraints imposed on theoverall system.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, ROM (ReadOnly Memory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The machine-readable media may be embodied in acomputer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

The methods disclosed herein comprise one or more steps or actions forachieving the methods. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims. Further, thevarious operations of methods described above may be performed by anysuitable means capable of performing the corresponding functions. Themeans may include various hardware and/or software component(s) and/ormodule(s), including, but not limited to a circuit, an applicationspecific integrated circuit (ASIC), or processor. Generally, where thereare operations illustrated in figures, those operations may havecorresponding counterpart means-plus-function components with similarnumbering.

The following claims are not intended to be limited to the aspects shownherein, but are to be accorded the full scope consistent with thelanguage of the claims. Within a claim, reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. No claim element is tobe construed under the provisions of 35 U.S.C. § 112(f) unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.” All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims.

What is claimed is:
 1. A method for wireless communication by a userequipment (UE), comprising: selecting a number of component carriers(CCs) in both a first frequency range and a second frequency range;determining a schedule for performing search and measurement in theselected number of CCs; and performing search and measurement in theselected CCs according to the determined schedule.
 2. The method ofclaim 1, wherein the number of CCs exceeds a number of narrow band (NB)radio frequency (RF) chains of the UE.
 3. The method of claim 1, whereinthe number of CCs are used for at least one of: dual connectivity (DC)involving different radio access technologies in the first and secondfrequency ranges; or carrier aggregation (CA) in at least one of thefirst and second frequency ranges.
 4. The method of claim 1, wherein thesearch and measurement is performed in the selected CCs using aplurality of UE beams.
 5. The method of claim 4, wherein: the secondfrequency range spans higher frequencies than the first frequency range;and one narrow band (NB) radio frequency (RF) chain is reserved for eachfrequency band of the second frequency range.
 6. The method of claim 5,wherein a single NB RF chain is used for search and measurement in allintra-band CCs of each frequency band.
 7. The method of claim 5, whereinthe schedule dictates: beam sweeping a plurality of UE beams to performsearch and measurement on a primary CC (PCC) at a first periodicity; andusing a selected one of the plurality of UE beams to perform search andmeasurement on at least one secondary CC (SCC) at a second periodicity.8. The method of claim 7, further comprising selecting the UE beam usedto perform search and measurement on the at least one SCC based on thebeam sweeping of the plurality of UE beams to perform search andmeasurement on the PCC.
 9. The method of claim 1, wherein: the secondfrequency range spans higher frequencies than the first frequency range;and at least two narrow band (NB) radio frequency (RF) chains arereserved for the first frequency range.
 10. The method of claim 9,wherein the schedule is based on a timer maintained for each CC of thefirst frequency range.
 11. The method of claim 10, wherein a number ofCCs, corresponding to a number of available narrow band (NB) radiofrequency (RF) chains of the UE, are selected based on values of thetimers maintained for each CC of the first frequency range.
 12. Themethod of claim 11, wherein, if multiple CCs have a same timer value, aCC with a shorter periodicity is given higher priority than a CC with alonger periodicity.
 13. An apparatus for wireless communication by auser equipment (UE), comprising: at least one processor and a memoryconfigured to: select a number of component carriers (CCs) in both afirst frequency range and a second frequency range; determine a schedulefor performing search and measurement in the selected number of CCs; andperform search and measurement in the selected CCs according to thedetermined schedule.
 14. The apparatus of claim 13, wherein the numberof CCs exceeds a number of narrow band (NB) radio frequency (RF) chainsof the UE.
 15. The apparatus of claim 13, wherein the number of CCs areused for at least one of: dual connectivity (DC) involving differentradio access technologies in the first and second frequency ranges; orcarrier aggregation (CA) in at least one of the first and secondfrequency ranges.
 16. The apparatus of claim 13, wherein the search andmeasurement is performed in the selected CCs using a plurality of UEbeams.
 17. The apparatus of claim 16, wherein: the second frequencyrange spans higher frequencies than the first frequency range; and onenarrow band (NB) radio frequency (RF) chain is reserved for eachfrequency band of the second frequency range.
 18. The apparatus of claim17, wherein a single NB RF chain is used for search and measurement inall intra-band CCs of each frequency band.
 19. The apparatus of claim17, wherein the schedule dictates: beam sweeping a plurality of UE beamsto perform search and measurement on a primary CC (PCC) at a firstperiodicity; and using a selected one of the plurality of UE beams toperform search and measurement on at least one secondary CC (SCC) at asecond periodicity.
 20. The apparatus of claim 19, further comprisingselecting the UE beam used to perform search and measurement on the atleast one SCC based on the beam sweeping of the plurality of UE beams toperform search and measurement on the PCC.
 21. The apparatus of claim13, wherein: the second frequency range spans higher frequencies thanthe first frequency range; and at least two narrow band (NB) radiofrequency (RF) chains are reserved for the first frequency range. 22.The apparatus of claim 21, wherein the schedule is based on a timermaintained for each CC of the first frequency range.
 23. The apparatusof claim 22, wherein a number of CCs, corresponding to a number ofavailable narrow band (NB) radio frequency (RF) chains of the UE, areselected based on values of the timers maintained for each CC of thefirst frequency range.
 24. The apparatus of claim 23, wherein, ifmultiple CCs have a same timer value, a CC with a shorter periodicity isgiven higher priority than a CC with a longer periodicity.
 25. Anon-transitory computer readable medium storing computer executable codethereon for wireless communication by a user equipment (UE), comprising:code for selecting a number of component carriers (CCs) in both a firstfrequency range and a second frequency range; code for determining aschedule for performing search and measurement in the selected number ofCCs; and code for performing search and measurement in the selected CCsaccording to the determined schedule.
 26. The computer readable mediumof claim 25, wherein the number of CCs exceeds a number of narrow band(NB) radio frequency (RF) chains of the UE.
 27. The computer readablemedium of claim 25, wherein the number of CCs are used for at least oneof: dual connectivity (DC) involving different radio access technologiesin the first and second frequency ranges; or carrier aggregation (CA) inat least one of the first and second frequency ranges.
 28. An apparatusfor wireless communication by a user equipment (UE), comprising: meansfor selecting a number of component carriers (CCs) in both a firstfrequency range and a second frequency range; means for determining aschedule for performing search and measurement in the selected number ofCCs; and means for performing search and measurement in the selected CCsaccording to the determined schedule.
 29. The apparatus of claim 28,wherein the number of CCs exceeds a number of narrow band (NB) radiofrequency (RF) chains of the UE.
 30. The apparatus of claim 28, whereinthe number of CCs are used for at least one of: dual connectivity (DC)involving different radio access technologies in the first and secondfrequency ranges; or carrier aggregation (CA) in at least one of thefirst and second frequency ranges.